Insulated wire



.Jan. 31, 1933. s. RUBEN 1,896,041

INSULATED WIRE Filed May 2, 1931 proofness due to the oil, is preferable in a is used the flexibility is increased; and where 100 Patented Jan. 31, 1933 UNITED, STATES PATENT OFFICE SAMUEL RUBEN, 01' NEW ROCHELLE, NEW YORK, ASSIGNOR '10 VEGA MANUFACTUR- ING CORPORATION, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE INSULATED WIRE Application filed Kay 2,

This invention relates to an imrpoved type of insulated wire.

An object of the invention is to produce a wire having a flexible refractory insulation.

A further object is the provision of a wire having a closely applied flexible insulating coating containing refractory inorganic material unaffected b high temperatures.

. Another object 1s.the provision of a wire having a refractory material applied and held on the wire by binders containing oilresinous substances.

A further object is to provide a wire having a refractor insulation which is durable and waterproo Another object is to provide a refractory wire coating containing finely divided chromium oxide held upon the wire in flexible form.

Further objects will be apparent from the disclosure and drawing in which is shown an insulated wire made in accordance with this invention.

This application is a continuation in part of my application filed December 3, 1930, Serial Number 499,845. As stated in that application, I have found that in order to properly coat a wire with an insulating material having the desired characteristics it is desirable also to have (1) a flexible binder of the resinous type to give a proper bond at low temperature and (2) a further binder, which material is to be effective at high temperature; this binder must be of the inorganic type such as boric acid or lead borate. This second and most im ortant binder serves two purposes; one, it binds the refractory and insulating material at high temperature; two, it prevents scaling and undesirable surface oxidation. In the aforementioned application I described a coating comprising generall a refractory oxide, a gum or resinous bin er and a borate or other inorganic relatively high temperature binding agent. In the "present case, the gum or resinous binder is specifically the oil enamel type. The oil-resinous binder, because of its high flexibility and water- 1981. Serial No. 584,711.

number of uses to the spirit varnish type of binder.

In the coating of this invention, the refractory oxide is preferably chromium sesqui-oxide although other materials have been used with satisfaction such as aluminum oxide, magnesium oxide,beryllium oxide, titanium oxide, zirconium oxide, iron oxide, and combinations of these, chromium used is preferably boric acid although other borates may be used. The materials used should be ground to as fine a state as possible. The organic hinder or carrier is of the organic type, such as enamel.

The first step in the preparation of the coating is the production of a gum or resinous carrier of the enamel type. In a typical enamel, I use 90 pounds'of resin or gum, 10 gallons of tung oil, 5 gallons of linseed oil, 1 pound of lead acetate, 5 gallons of turpentine and 35 gallons of mineral thinner. The resin, tung oil and 3 gallons of linseed oil are heated to about 540 Fahrenheit. The mixture is then pulled from the fire, the lead acetate, the remaining gallon and half of linseed oil, the turpentine and the mineral thinner are added and the whole heated to about. 420 Fahrenheit.

A desirable coating is made by grinding materials in the following proportions: To 450 cc. of the prepared enamel I add 200 grams of chromium sesqui-oxide and 100 grams of boric acid, the mixture being milled until the various materials are thoroughly ground. The amounts given are not critical and the composition of the coating may be varied by increasing or decreasing the respective amounts of the enamel or of the oxides, depending upon the flexibility or insulation desired; that is to say, when more oil enamel more dxide is used the refractoriness of the insulation is increased.

A continuous coating. process is used in applying the insulation to the wire. The wire passes through cups containing the insulatin compound or mixture, being heated and ba ed in furnaces located between the cups. During the heating, the inorganic binder, the boric acid, melts and binds the refractory oxide crystals, a eat part of the or anic materials being ba ed 0 lflven though the wire, inuse, is heated to a point where the organic binder, is disengaged, no harm results due to the presence of.

the inorganic binder, boric acid. The use of this borate in the coating is also of assistance in dispensin with the necessity of a flux in soldering the wire, particularly when copper wire is coated.

The formula for making the enamel carrier or relatively low tem erature binder may, of course, be varied. racticall all of the baking enamels will act as suit-a le carriers for the refractory oxide and the borate.

In the accompanying drawing, illustrative of the invention, the copper wire (1), has an insulating coating thereon consisting of a mixture (2) of an oil resinous varnish, finely divided chromium sesqui-oxide and boric acid which has been baked upon the wire.

- I claim:

1. A wire having on its surface a closely adherent layer of flexible refractory insulation n which the refractory material consists substantially of finely divided chromium oxide, held upon the wire by a baked 01lresinous enamel binder.

2. A wire having on its surface a closely adherent layer of a flexible refractory insulation consisting substantially of finely divided titanium oxide, held upon the wire by a baked oil-resinous enamel binder.

3. A wire having on its surface a closely adherent layer of a flexible refractory insulation consistin substantially of finely divided iron oxide, he d upon the mm by a baked oilresinous enamel binder.

4. An insulated wire having a coating of a finely divided insulating material held together with an enamel of the oil-resinous type and an inorganic binder capable of withstanding high temperature.

5. A wire having on its surface a closely adherent layer of flexible refractory insulation consisting substantially of the combination of non-fibrous inorganic insulating matter and an inorganic binding material, held upon the wire by an oil-resinous binder.

6. A wire havin on its surface a closely adherent layer of exible refractory insulatior'rconsistln substantially of the combination of non-fi rous inorganic insulating mattiafi'and a boron compound, held uponthe ygire by an oil-resinous binder. 7. A wire having on its surface a closely 8. A wire having on its surface a closely adherent layer of flexible refractory insulation consisting substantially of the combination of finely divided insulating oxide and boric acid, held upon the wire by an oil-resinous binder. 7

9. A wire having on its surface a closely adherent flexible insulating layer consisting of a mixture of finely divided insulating oxide, an oilresinous binding material and an inorganic binder compound effective at elevated temperatures.

10. A wire having a flexible insulating coating consisting of finely divided nonfibrous inorganic insulating material, a boron coulipound and an oil-resinous binding'mater1a 11. A wire having a flexible insulating coating consisting of finely divided insulating oxide, a boron compound-and an oilresinous bindin material.

12. A wire aving a flexible insulating coating consisting of a plurality of baked on layers of a mixture of finely divided nonfibrous inorganic insulating material, an oilresinous binder material and an inorganic binder compound, effective at elevated temperatures.

13. A wire havin a flexible insulating coating consistin o a baked mixture of finely divided ox1de, an oil-resinous binder material and an inorganic binder compound effective at elevated temperatures.

14. A wire having. a flexible insulating coating consistin of a baked mixture of finely divided nonbrous inor anic insulatin material, an oil-resinous bin er material an boric acid.

15. A wire having on its surface, a closely adherent flexible insulating layer consisting of a mixture of finely divided inorganic insulating material, a vegetable oil-resinous enamel and an inor anic binding material capable of withstan ing high temperatures.

16. A wire having on its surface a closely adherent flexible insulatinglayerofa mixture of finely divided oxide, a vegetable oil-resinous enamel. and an inorganic bindingcompound effective .at high temperatures.

17. An insulated wire having a coatin consisting substantially of finely divided oxide, a vegetable oil-resinous enamel and a boron com ound.

18. An insulated wire having a coating containin finel divided chromium sesquioxide hel toget er with an oil enamel binder and an inorganic binder effective at elevated temperatures.

19. An insulated wire having a coating containing finely divided chromium oxide held to 'ether and upon the wire by an oil enamel binder and a second binder composed of a borate.-

20. An insulated wire having a coating containing finely divided chromium sesquioxide held together and upon the wire by an oil enamel binder and a second binder of boric acid 21. A wire having on its surface, a closely adherent flexible insulating layer consisting of a baked mixture of finely divided chromium oxide, an oil-resinous binding material and an inorganic binder compound effective at elevated temperatures.

22. A copper wire having on its surface a flexible insulating coating consisting of finely divided chromium oxide, an oil-resinous binding material and a boron compound.

23. A wire having a flexible insulating coating consisting substantially of finely divided titanium oxide, an oil-resinous binding material and an inorganic binder compound effective at elevated temperatures.

24. A wire having a flexible insulating coating consisting substantially of finely divided titanium oxide, an oil-resinous binding material and a boron compound.

25. A wire having a flexible insulating coating consisting substantially of finely divided iron oxide, an oil-resinous binding material and an inorganic binder compound effective at elevated temperatures.

26. A wire having a flexible insulating coating consisting substantially of finely divided iron oxide, an oil-resinous binding material and a boron compound.

In testimony whereof, I afiix m signature.

' SAMUEL UBEN. 

